While completing the External Sensors Lab, students learned the importance of sensors when controlling the Advanced Energy Vehicle. Instead of instructing the AEV to travel for a time interval, students programmed the AEV to travel specific distances. In this way the team controlled the AEV’s movement along the track with greater accuracy, though Group B faced with some troubleshooting difficulty in the learning process. These accurate instructions allow the team to complete essential steps in the mission scenario, including navigating the discrete paths between the visitor venter, entrance gate, and storage facility.
Figure 1: Scenario
Figure 2: Code
The reflectance sensors allowed the AEV to travel a fixed distance along the track. Information from each sensor was used with a function called “gotoabsoluteposition()”, as seen in Figure 2 in the appendix. That command was used to supply power to the motors until the parameters of the function were satisfied, ensuring that distance traveled was accurate and under greater control of the team. The command “gotorelativeposition()” may have been used to make the AEV travel distances relative to its current location, though none of the lab scenario directions required this and it was not used. These commands and sensors will be used in the scenario in the Mission Concept Review. It would allow the team to instruct the AEV to travel specific distances, such as the 21 foot path between each stopping point on the track.